Here's the changelog for Windows 10 Build 10586.218 (PCs)

Today, Microsoft released Windows 10 Build 10586.218 worldwide. The latest update is available as a cumulative update (KB3147458 and KB3147461). As per usual, the latest cumulative update does not introduce any new features as expected, but it does introduce some new improvements and bug fixes. Here is the changelog:

• Improved reliability for Internet Explorer 11, .NET Framework, wireless LAN, Microsoft Edge, Windows Update, logon, Bluetooth, network connectivity, map apps, video playback, Cortana, USB, Windows Explorer, and Narrator.
• Fixed issue with connectivity of USB devices until OS restart.
• Improved discoverability of printers when a device resumes from sleep.
• Fixed issues with lock screen.
• Support for visual voicemail on dual SIM phones.
• Fixed issue with audio playback using Groove music and other music apps on a phone.
• Fixed issue with revised daylight savings time.
• Fixed additional issues with shutdown delays, Narrator, Cortana, roaming data usage, buying apps in the Store, video playback, facial recognition, Bluetooth pairing, Microsoft Edge, logon, Internet Explorer 11, Live Tile updates, .NET Framework, and Microsoft Installer (MSI).
• Improved security for CSRSS to address security feature bypass.
• Fixed additional security issues with Security Account Manager Remote Protocol, HTTP.sys, secondary logon, Microsoft Graphics component, .NET Framework, CSRSS, Microsoft Edge, and Internet Explorer 11.

As you can see from the above changelog, Microsoft is improving the reliability for some of the parts of the OS with the latest update. The update also includes security update, so it is quite important to get the latest update installed on your PC.

If you want to get the latest update, just head over to Settings > Update & Security and check for updates.